Link establishment between a radio equipment controller (rec) and radio equipment (re) in a fronthaul network

ABSTRACT

Techniques that provide link establishment between a radio equipment controller (REC) and a radio equipment (RE) in a fronthaul network are described herein. In one embodiment, a method includes performing, Common Public Radio Interface (CPRI) Layer 1 (L1) link auto-negotiation operations to establish a CPRI link between the REC and RE. A proxy slave may achieve a hyper frame number (HFN) synchronization with the REC at a link bit rate for a first CPRI bit stream and communicate the first CPRI bit stream and the link bit rate to a proxy master. The proxy master may communicate a second CPRI bit stream to the proxy slave to transmit to the REC. The L1 link auto-negotiation operations are completed and CPRI link is established between the REC and the RE when the REC achieves a HFN synchronization for the second CPRI bit stream.

PRIORITY CLAIM

This application claims priority to Indian Provisional Application No.201941003988, entitled “FRONTHAUL NETWORK SOLUTIONS,” filed on Feb. 1,2019, the disclosure of which application is hereby incorporated byreference in its entirety.

TECHNICAL FIELD

The present disclosure relates to communication systems, in particular,to techniques to provide link establishment between a radio equipmentcontroller (REC) and radio equipment (RE) in a fronthaul network.

BACKGROUND

Mobile networking architectures have grown increasingly complex incommunication environments. In particular, access network configurationsfor mobile networking architectures have become more complex. As accessnetwork configurations become more complex, facilitating communicationsamong access network elements such as a radio equipment controller andradio equipment becomes more critical. Accordingly, there aresignificant challenges in facilitating communications between a radioequipment controller and radio equipment in a network.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified diagram again illustrating example detailsassociated with Common Public Radio Interface (CPRI) link bit ratenegotiation.

FIG. 2 is a simplified diagram illustrating example details associatedwith a fronthaul network in which techniques to provide linkestablishment between a radio equipment controller and a radio equipmentmay be implemented, according to an example embodiment.

FIG. 3 is a simplified diagram illustrating example details associatedwith operations to provide link establishment between the radioequipment controller and the radio equipment of the fronthaul network ofFIG. 2, according to an example embodiment.

FIGS. 4A-4C are simplified diagrams illustrating example detailsassociated with an Ethernet frame including an Radio over Ethernet (RoE)frame that may be used to communicate link bit rate information,according to an example embodiment.

FIG. 5 is a simplified flowchart illustrating example operations toprovide link establishment between an REC and RE in a fronthaul network,according to an example embodiment

FIG. 6 is a simplified flowchart illustrating example operations tocommunicate link bit rate information using a RoE header of a RoE frame,according to an example embodiment.

FIG. 7 is a simplified block diagram illustrating example detailsassociated with a Proxy Master node for implementing operationsdescribed herein, according to an example embodiment.

FIG. 8 is a simplified block diagram illustrating example detailsassociated with a Proxy Slave node for implementing operations describedherein, according to an example embodiment.

FIG. 9 is a simplified block diagram illustrating example detailsassociated with a radio equipment controller for implementing operationsdescribed herein, according to an example embodiment.

FIG. 10 is a simplified block diagram illustrating example detailsassociated with a radio equipment for implementing operations describedherein, according to an example embodiment.

DESCRIPTION OF EXAMPLE EMBODIMENTS Overview

Provided herein are techniques associated with link establishmentbetween a radio equipment controller (REC) and a radio equipment (RE) ina fronthaul network. Using techniques discussed for embodimentsdescribed herein, a network operator can deploy Common Public RadioInterface (CPRI)-based REC and RE of varied capabilities in a fronthaulnetwork and the techniques discussed for embodiments herein can be usedto achieve end-to-end CPRI link synchronization between the REC and RE.

In one embodiment, a computer-implemented method is provided and mayinclude performing, for one or more link bit rates of a plurality oflink bit rates configured for a fronthaul network, Common Public RadioInterface (CPRI) Layer 1 link auto-negotiation operations to establish aCPRI link between a radio equipment controller and a radio equipment ofthe fronthaul network, the CPRI Layer 1 link auto-negotiation operationscomprising: achieving, by a proxy slave, a hyper frame numbersynchronization with the radio equipment controller at a link bit ratefor a first CPRI bit stream transmitted by the radio equipmentcontroller; communicating the first CPRI bit stream and the link bitrate from the proxy slave to a proxy master; transmitting, by the proxymaster, the first CPRI bit stream to the radio equipment at the link bitrate and the radio equipment attempting to achieve a hyper frame numbersynchronization with the first CPRI bit stream; upon the radio equipmentachieving the hyper frame number synchronization, the radio equipmentcommunicating a second CPRI bit stream to the proxy master at the linkbit rate; upon the proxy master achieving a hyper frame numbersynchronization with the radio equipment for the second CPRI bit streamtransmitted by the radio equipment at the link bit rate, communicatingthe second CPRI bit stream from the proxy master to the proxy slave; andtransmitting, by the proxy slave, the second CPRI bit stream to theradio equipment controller, wherein the Layer 1 link auto-negotiationoperations are completed and the CPRI link is established between theradio equipment controller and the radio equipment when the radioequipment controller achieves a hyper frame number synchronization forthe second CPRI bit stream transmitted by the proxy slave at aparticular link bit rate. All this occurring within a fixed transmittime interval for a link bit rate on the radio equipment controllerensures the Layer 1 link auto-negotiation operations are completed andthe CPRI link is established between the radio equipment controller andthe radio equipment when the radio equipment controller achieves a hyperframe number synchronization for the CPRI bit stream transmitted by theproxy slave.

Example Embodiments

Communications in a network environment can be referred to herein as‘messages’, ‘messaging’, ‘signaling’, ‘data’, ‘content’, ‘objects’,‘requests’, ‘queries’, ‘responses’, ‘replies’, etc. which may beinclusive of packets. As referred to herein and in the claims, the term‘packet’ may be used in a generic sense to include packets, frames,segments, datagrams, and/or other generic data units that may be used totransmit communications (e.g., data and/or commands) in a network. Apacket is a formatted unit of data that can contain control or routinginformation (e.g., source and destination address, etc.) and data, whichis also sometimes referred to as a payload or data payload. In someembodiments, control or routing information, management information, orthe like can be included in packet fields, such as within header(s)and/or trailer(s) of packets.

The terms ‘data’, ‘information’, ‘parameters,’ and the like as usedherein can refer to any type of binary, numeric, voice, video, textualor script data or information or any type of source or object code, orany other suitable data or information in any appropriate format thatcan be communicated from one point to another in electronic devicesand/or networks. Additionally, messages, requests, responses, replies,queries, etc. are forms of network traffic and, therefore, may compriseone or more packets.

Communications in a network environment can be sent and receivedaccording to any suitable communication protocols. Suitablecommunication protocols can include a multi-layered scheme such as theOpen Systems Interconnection (OSI) Model, or any derivations or variantsthereof. Internet Protocol (IP) addresses discussed herein and in theclaims can include IP version 4 (IPv4) and/or IP version 6 (IPv6)addresses. For example, various Layer 1 (L1 ) and/or Layer 2 (L2)communications/operations may be referenced herein.

Architectures that facilitate network communications generally rely uponthree basic components: a data or user plane, a control plane, and amanagement plane. Typically, the user plane carries data traffic (e.g.,user data traffic), while the control plane and the management planeserve the data plane. As referred to herein and in the claims, the term‘plane’ can refer to a separation of traffic, operations, etc. for anetwork and/or network element or node.

In general, 3rd Generation Partnership Project (3GPP) mobile networkarchitectures such as 3GPP Long Term Evolution (LTE) architectures,sometimes referred to as 4th Generation (4G)/LTE architectures, as wellas 3GPP 5th Generation (5G) architectures can be implemented via a corenetwork and one or more 3GPP access networks in which user equipment(UEs) connect to a core network via over-the-air Radio Frequency (RF)communications with radio units or radio equipment (RE) of the accessnetworks. Some 3GPP access networks can be implemented in aconfiguration that includes a radio equipment controller (REC) thatinterfaces with the core network and also that interfaces with one ormore RE. In some instances, an REC may also be referred to as a BasebandUnit (BBU) and an RE may be referred to as a Remote Radio Head (RRH).Both the REC and RE are two basic building blocks of a radio basestation. The REC is concerned with the Network Interface transport, theradio base station control and management as well as the digitalbaseband processing. The RE provides the analogue and radio frequencyfunctions via a radio head such as filtering, modulation, frequencyconversion and amplification or, more generally, RE serves as the airinterface, to the user equipment.

In current deployments of co-located REC and RE, the Common Public RadioInterface (CPRI) is used as directly connected bi-directionalpoint-to-point over fiber. In general, CPRI is a point to point bitsynchronous serial data link between the co-located REC and the REproviding an ‘always ON constant bit rate’ steady data stream. Asreferred to herein, the terms ‘data link’ and ‘link’ can be usedinterchangeably.

Referring to FIG. 1, FIG. 1 is a simplified diagram 100 illustratingexample details associated with CPRI link bit rate negotiation. FIG. 1illustrates the transmit link bit rates 102 for a CPRI bit streamtransmitted by the master port (REC) and receive/decode link bit rates104 at which a slave port (RE) attempts to receive and decode the masterport (REC) transmitted CPRI bit stream in relation to times110(1)-110(3), as represented along a time axis 110.

A CPRI link negotiation is performed to negotiate a common matching linkbit rate for establishing the bi-directional CPRI data link betweenco-located REC and RE. CPRI Specification version 7.0 (v7.0), publishedOctober 9, 2015, describes the current procedure for link negotiationbetween REC and RE in direct connected deployments, in which the masterport (REC) drives the link bring-up with the slave port (RE) and linkbit rate auto negotiation, L1 synchronization, and framesynchronization/alignment all happen together directly between theco-located REC and RE. For CPRI Specification v7.0, bit rate is referredto as ‘line bit rate’; however, for purposes of discussions herein, theterm ‘link bit rate’ will be used. Further as referred to herein, theterms ‘link auto-negotiation’, ‘link negotiation’, and ‘link bit-ratenegotiation’, may be used interchangeably. Further as referred toherein, the terms ‘synchronization’ and ‘sync’ may be usedinterchangeably.

CPRI L1 synchronization accomplishes two things between the master andslave ports: byte alignment and hyper frame alignment for CPRI bitstreams transmitted via the data link between the co-located REC and REat a common matching link bit rate for the master and slave. Followingframe synchronization/alignment, negotiations associated with protocolsetup and control and management (C&M) setup, also referred to as L2negotiations, are performed to determine a highest common matching linkbit rate for the master and slave (if not already selected during the L1sync) and also to determine a CPRI (in-band) C&M channel bit rate, C&Mprotocol, and vendor specific negotiations/signaling.

Current CPRI Link Auto-Negotiation:

The following procedure is used to arrive at a common matching link bitrate as per CPRI Specification v7.0:

Master Port Actions:

1. The master port starts to transmit a CPRI bit stream at the highestavailable link bit rate directly and also starts to attempt receiving aCPRI bit stream (e.g., from the slave port) at the same link bit rate.If the frame alignment is not reached with the slave port, it selectsthe next highest link bit rate from its rate table (e.g., capabilityset) for transmission after a T1 time interval (0.9-1.1 seconds), ifavailable.

2. Each following T1 time interval, a new link bit rate is chosen fortransmission and reception (if available).

3. The link bit rates are selected from the available set in a roundrobin fashion, i.e. the first highest, the second highest, and so on tothe slowest, and then restarting from the highest link bit rate.

Slave Port Actions:

1. The slave port starts attempting to receive a CPRI bit stream (e.g.,from the master port) at the highest available link bit rate directly.If the frame alignment is not reached with master port, it selectsanother link bit rate for CPRI bit stream reception after a T2 timeinterval (3.9-4.1 seconds), if available.

2. Each following T2 time interval, a new reception link bit rate ischosen for reception (if available).

3. The link bit rates are selected from an available set (sometimesreferred to as a ‘capability set’) in a round robin fashion, i.e., thefirst highest, the second highest, and so on to the slowest, and thenrestarting from the highest link bit rate.

4. When the slave port reaches a hyper frame number (HFN) sync it startstransmitting a CPRI bit stream toward the master port on the same linkbit rate. As prescribed by CPRI Specification v7.0, HFN sync is achievedby a CPRI port upon four consecutive successful detections of a SYNCbyte in a CPRI bit stream received by the CPRI port. When the masterport is able to receive and decode the slave port transmitted CPRI bitstream (e.g., achieve HFN sync), since the master port is also tuned atthe same link bit rate, the link negotiation is considered complete andL1 synchronization is achieved as both nodes are able to communicatewith each other now.

The above 7 steps are repeated until a common link bit rate match isachieved between the co-located REC and RE. Per CPRI Specification v7.0Section 4.5.2, the above steps/actions are associated with a start-upprocess that is implemented via a CPRI port state machine configured forthe CPRI interface elements/ports of the REC and RE in which operations,events, and transitions through states of the CPRI port state machineare prescribed according to CPRI Specification v7.0.

Consider an example as illustrated in FIG. 1. If the master port (REC)has a capability set in which it is capable of {9.8, 4.9, 2.5, and 1.2}Gigabits per second (Gbps) CPRI link bit rates and the slave port (RE)is capable of {2.5 and 1.2} Gbps CPRI link bit rates, the followingoccurs:

-   -   Master port starts transmitting a CPRI bit stream at a time        110(2) and changes it's transmit link bit rate 102 after every        T1 (09-1.1. seconds) time interval 112.    -   Slave port starts attempting to receive/decode at a time 110(1)        (earlier than the time 110(2) at which the master port starts        transmitting) and changes its receive/decode link bit rate 104        after every T2 (3.9-4.1 seconds) time interval 114.    -   Both continue until a matching link bit rate is found and HFN        sync is achieved, as shown ata time 110(3).

While the link negotiation procedure can be performed according CPRISpecification v7.0 when the REC and RE are co-located and directlyconnected, the procedure cannot work in fronthaul networks in which theREC and RE are interconnected through one or more intermediate nodes viaa packet-based network, such as an Ethernet network.

The presence of the intermediate nodes in a fronthaul network poses adiscontinuity problem for establishing the CPRI link negotiation (e.g.,comprising link bit rate negotiation, L1 synchronization, and framesynchronization/alignment) between the REC and RE using the processprescribed by CPRI Specification v7.0. In fronthaul networks, the RECand RE endpoints cannot communicate directly with each other due topresence of CPRI interfacing Ethernet nodes as all these nodes may berunning at different rates. Without having a commonly understandableCPRI link bit rate across the entire CPRI path for the CPRI interfacingnodes, the end-to-end CPRI link negotiation cannot be achieved.

Fronthaul Nomenclature

In a fronthaul network, the REC and RE do not interact directly; ratherEthernet nodes capable of CPRI mapping and de-mapping (e.g., mapping andde-mapping between a CPRI bit stream and Ethernet frames and vice-versa,depending on the direction of communications) interface with the REC andRE. The Ethernet node capable of CPRI mapping/de-mapping connecteddirectly to the REC is referred to herein as a ‘Proxy Slave’ or a ‘CPRIProxy Slave’ and the Ethernet node capable of CPRI mapping/de-mappingconnected directly to the RE is referred to herein as a ‘Proxy Master’or a ‘CPRI Proxy Master’. The Proxy Master and the Proxy Slave nodes maybe referred to generally as ‘proxy nodes’.

In a typical fronthaul network, the Proxy Master and Proxy Slave cancommunicate over a packet-based network, such as an Ethernet network,using Radio over Ethernet (RoE) communications, as prescribed by theInstitute of Electrical and Electronics Engineers (IEEE) 1914.1 and IEEE1914.3 Specifications, approved Sep. 27, 2018. IEEE 1914.1 and 1914.3(referred to herein as ‘IEEE 1914 standards’) provide standards forencapsulation and mapping/de-mapping of radio data, such as CPRI bitstreams, and/or potentially control and/or management packets withinEthernet frames. For a given Ethernet frame, radio data and/orpotentially control and/or management packets can be included within aRoE frame that is encapsulated in the Ethernet frame. As discussed infurther detail herein, a RoE frame can include an RoE header and an RoEpayload.

The IEEE 1914 standards define different RoE mappers/de-mappers,including: structure-aware, structure-agnostic, and native mode in whichstructure-aware mapping/de-mapping operations can be used for CPRI data,structure-agnostic mapping/de-mapping operations can be used for anydigitized radio data, and native mode mapping/de-mapping operations canbe used for digitized radio In-phase/Quadrature (I/Q) payload data.

The structure-agnostic RoE mapper is considered for embodimentsdescribed herein. While the IEEE 1914.1 and IEEE 1914.3 Specificationsprovide standards for encapsulation and mapping/de-mapping of CPRI bitstreams over packet-based fronthaul transport networks, the standards donot cover how end-to-end link negotiations can be performed between anREC and RE in fronthaul networks.

Further, current CPRI link negotiation processes as prescribed by CPRISpecification v7.0 will not work in fronthaul networks. Recall, the keypoints for end-to-end CPRI link negotiation as prescribed by CPRISpecification v7.0 are:

1. That the HFN sync shall be achieved directly between REC and RE.

2. That the current non-fronthaul CPRI negotiation is a probabilisticmethod as the slave and master attempt different link rates at the sametime. Rates are changed at both ends after different intervals; themaster changes the link rate for transmission every 0.9-1.1 seconds andthe slave changes the link rate for reception every 3.9-4.1 seconds.Using the method as prescribed by CPRI Specification v7.0 for anon-fronthaul network, both tend to reach at a common match. If thematch does not happen in one iteration of 3.9-4.1 seconds, the procedureis repeated again.

However, in a fronthaul network, when using current CPRI linknegotiation processes as prescribed by CPRI Specification v7.0, thefollowing can occur:

1. The REC will start at one rate and the Proxy Slave will engage inlocal CPRI negotiations with the REC. A common match will be foundduring this negotiation. However, the Proxy Slave still needs to involvethe RE in this process.

2. At this stage, the Proxy Slave will start communications towards theProxy Master (and the RE) using the same rate. The problem here is thatthe Proxy Master is also not tuned for this rate at this point.

3. Say, for example, that the Proxy Master also tunes to this same rateusing some control channel communication with the Proxy Slave, the ProxyMaster then needs to involve RE in this procedure. The time taken inthis communication is a key variable affecting the whole end-to-endnegotiation.

4. At this stage, the Proxy Master will first need to ensure that thisabove rate is supported at the RE using the same CPRI link negotiationprocedure.

5. Carrying out the steps 2-4 will take time and due to the delay, whatwill happen is that that the REC (the original Master) will have movedto a different bit rate already by the time the Proxy Slave and the REreaches a common rate. Thus, this whole procedure will be repeated againand again. It should be noted that there is only the prescribed windowof 0.9-1.1 seconds in which steps 2-4 need to be carried out in orderfor the HFN sync to be achieved between REC and RE, otherwise theoverall negotiation may not be achieved at all.

One possible solution arriving at a common link rate on all nodesincluding the REC and RE in the CPRI path flow may be to use a manualstatic configuration at all CPRI endpoints and the intermediate CPRIinterfacing nodes; however, such a solution is error prone, inefficientat times, and not scalable.

Example embodiments described herein provide techniques to overcomethese hurdles by providing a mechanism to provide CPRI linkestablishment between an REC and an RE in an Ethernet-based fronthaulnetwork. A CPRI link for a fronthaul network is a cross product of CPRIand Ethernet as the end-to-end nodes (REC/RE) use CPRI only tocommunicate with each other via the proxy nodes, which performmapping/de-mapping and link monitoring operations. Thus, embodimentsdescribed herein may facilitate end-to-end CPRI link synchronizationbetween an REC and an RE in which the REC represents one end and the RErepresents another end of the end-to-end CPRI link synchronization.

Referring to FIG. 2, FIG. 2 is a simplified diagram illustrating exampledetails associated with a fronthaul network 200 in which techniques toprovide link establishment between an REC 210 and RE 220 may beimplemented, according to an example embodiment. FIG. 2 includes REC210, RE 220, a Proxy Slave 230, a Proxy Master 240, and an Ethernetnetwork 250. As referred to herein, REC 210 may also be referred to asthe ‘CPRI Master’ and RE 220 may be referred to as the ‘CPRI Slave’.Further as referred to herein, fronthaul network 200 may also bereferred to as an Ethernet-based fronthaul network 200.

In at least one embodiment, at least one CPRI interface element/port maybe configured for each of Proxy Slave 230 and Proxy Master 240 in whichthe CPRI port state machine may be configured for the CPRI interfaceelement/port for each of Proxy Slave 230 and Proxy Master 240. Asdiscussed for embodiments herein, some operations of Proxy Slave 230involving L1 link negotiations/sync with REC 210 may differ from thestandard negotiation/sync processes as described by CPRI Specificationv7.0, while other operations, such as updating internal states of theCPRI port state machine for REC 210 may follow the processes describedby CPRI Specification v7.0. In at least one embodiment, at least oneEthernet interface element/port may also be configured for each of ProxySlave 230 and Proxy Master 24 to facilitate communications via Ethernetnetwork 250.

As illustrated in FIG. 2, the interconnection between REC 210 and ProxySlave 230 is a CPRI interconnection, the interconnection between ProxySlave 230 and Ethernet network 250 is an Ethernet interconnection, theinterconnection between RE 220 and Proxy Master 240 is a CPRIinterconnection, and the interconnection between Proxy Master 240 andEthernet network 250 is an Ethernet interconnection. REC 210 may furtherinterface with a 3GPP mobile core network (not shown).

Proxy Slave 230 is an Ethernet node connected directly to REC 210 andalso to Ethernet network 250. Proxy Slave 230 is capable of performingCPRI mapping and de-mapping for various communications/operations withinfronthaul network 200, as discussed herein. Proxy Master 240 is anEthernet node connected directly to RE 220 and also to Ethernet network250. Proxy Master 240 is capable of performing CPRI mapping andde-mapping for various communications/operations, as discussed herein.Proxy Slave 230 and Proxy Master 240 may interface with each other usingEthernet-based communications using Ethernet network 250.

RoE frames encapsulated within Ethernet frames may be utilized forcommunications of radio data to/from REC 210 and RE 220 in which ProxySlave 230 and Proxy Master 240 can map/de-map CPRI bit streams to/fromRoE frames for communications across Ethernet network 250 and with eachof REC 210 and RE 220 (e.g., via the CPRI interconnection between ProxySlave 230 and REC 210 and also via the CPRI interconnection betweenProxy Master 240 and RE 220) to facilitate end-to-end communicationsbetween REC 210 and RE 220.

As noted above, the structure-agnostic RoE mapper is considered forembodiments described herein. In at least one embodiment, as discussedin further detail herein, a RoE header of an RoE frame may be enhancedto include link bit rate information to facilitate end-to-end L1 linkauto-negotiation operations and CPRI link establishment between REC 210and RE 220 for fronthaul network 200.

Referring to FIG. 3, FIG. 3 is a simplified diagram illustrating exampledetails associated with operations 300 to provide link establishmentbetween the REC 210 and RE 220 of the fronthaul network 200 of FIG. 2,according to an example embodiment.

In at least one embodiment, operations 300 to provide L1 linkauto-negotiation and link establishment between the REC 210 and RE 220may be generally performed as follows:

301: Proxy Slave 230 tries to establish HFN sync with REC 210.

302: On achieving HFN sync, Proxy Slave 230 does not transmit back toREC 210 but starts sending RoE frames (within Ethernet frames) towardsProxy Master 240 along with indicating the link rate at which the HFNsync was achieved with REC 210 in the RoE header of the RoE frames.

303: Proxy Master 240 decodes the link bit rate information from the RoEheader and transmits the CPRI stream from received the RoE framestowards the RE 220.

304: RE 220 decodes the CPRI bit stream successfully at some point intime and achieves HFN sync with the received CPRI bit stream (which wasoriginated at REC 210).

305 [collectively, 305(1), 305(2), and 305(3)]: RE 220 startstransmitting a CPRI bit stream towards REC 210 through proxy nodes(e.g., Proxy Master 240 and Proxy Slave 230) at the link bit rate atwhich the HFN sync was achieved. Successful decoding of the CPRI bitstream at REC 210 will culminate or complete the L1 linkauto-negotiation procedure between the REC 210 and RE 220 to establish aCPRI data link between the REC 210 and RE 220.

Additional details related to operations 300 are provided herein, below.Before discussing the additional details associated with operations 300,various pre-requisites for L1 link auto-negotiation may be considered.In various embodiments, pre-requisites for starting operations 300associated with L1 link auto-negotiation between REC 210 and RE 220 mayinclude, but not be limited to: that Proxy Slave 230 and Proxy Master240 are configured or otherwise synchronized using a control protocol tohave common subset of link bit rates (e.g., they do not necessarily haveto have the same set of link bit rates); the same RoE mapperType valueis set to be the same at both Proxy Slave 230 and Proxy Master 240(i.e., both support the same mapperType mode of either the Tunnelingmode or the Line coding aware mode, as specified in the IEEE 1914standards); that packet-based communication between Proxy Slave 230 andProxy Master 240 via Ethernet network 250 is operational; and that REC210 and RE 220 of varied link bit rate capabilities are set up and readyfor L1 link negotiation in fronthaul network 200. Other pre-requisitesfor starting operations 300 may be considered, as discussed herein.

In at least one embodiment, operations 300 may begin at 301 at whichProxy Slave 230 will try to establish HFN sync with REC 210. Proxy Slave230 will follow the standard procedure described in CPRI v7.0Specification for the operations at 301 in which REC 210 will transmit aCPRI bit stream and change its transmit link bit rate every T1 timeinterval (i.e., 0.9-1.1 seconds) and Proxy Slave 230 will be selectingdifferent line bit rates for reception after every T2 time interval(i.e., 3.9-4.1 seconds).

However, differing from standard link negotiation operations describedin CPRI v7.0 Specification, on reaching HFN sync at 301, Proxy Slave 230will not transmit back towards REC 210 at the link bit rate. Rather, theoperations may include, at 302, Proxy Slave 230packetizing/encapsulating the CPRI bit stream received from REC 210 intoRoE frames (e.g., into the RoE payload of RoE frames) and transmittingthe RoE frames encapsulated within Ethernet frames (towards the RE 220direction) to Proxy Master 240 via Ethernet network 250. In the RoEheader of the RoE frames, Proxy Slave 230 will indicate the current CPRIlink bit rate with which it has achieved the HFN sync with REC 210. Forexample, in at least one embodiment, 4-bits from the optional reservedbits field in the orderInfo—seqNum field in the RoE header can be usedfor carrying the CPRI link bit rate information from Proxy Slave 230 toProxy Master 240 during L1 link auto-negotiation operations. Additionaldetails related to use of the RoE header to communicate link bit rateinformation are discussed below with reference to FIGS. 4A-4C.

Referring again to FIG. 3, the operations may further include, at 303,Proxy Master 240, on receiving the RoE frames from Proxy Slave 230,determining the CPRI link bit rate information from the RoE header andbegin playing out (e.g., transmitting) the CPRI bit stream towards theRE 220 as per the same CPRI link bit rate determined from the RoE headerof the RoE frames. For example, Proxy Master 240 can use the receivedRoE frames and extract out/de-map the radio data from the received RoEframes to transmit the CPRI bit stream to RE 220 at 303.

It should be noted that Proxy Master 240 will receive the RoE framesafter a propagation delay from REC 210 to Proxy Master 240. However, thepropagation delay will be very small (less than a millisecond) ascompared to the overall time window of T1 time (0.9-1.1 seconds) thatoccurs before REC 210 will move to a new link bit rate.

As Proxy Master 240 is transmitting the CPRI bit stream at 303, theoperations may include, simultaneously at the other end of the CPRIinterconnection with Proxy Master 240, the CPRI port of RE 220 isattempting, at 304, to receive and decode the CPRI bit stream directlyat the highest available link bit rate for the capability set configuredfor RE 220.

As per the standard CPRI v7.0 Specification procedure, RE 220 will beselecting, at 304, different line bit rates after every T2 time interval(3.9-4.1 seconds) and will be repeating the same procedure of attemptingto receive the CPRI bit stream until RE 220 achieves the HFN sync (i.e.,four consecutive successful detections of the SYNC byte in the receivedCPRI bit stream). Thus, the operations at 301, 302, 303, and 304 will berepeated again and again for different link bit rates at REC 210 and RE220 as per the REC T1 transmit time interval (0.9-1.1 seconds) and REC210 T2 time intervals (3.9-4.1 seconds) in which REC 210 continuesselecting a new link bit rate for transmission and reception after everyT1 time interval (0.9-1.1 seconds) until RE 220 achieves the HFN syncfor the CPRI bit stream transmitted by Proxy Master 240.

Upon RE 220 reaching HFN sync, the operations may include, at 305(1), RE220 starting to transmit a CPRI bit stream to Proxy Master 240 using thesame link bit rate at which the HFN sync was achieved by RE 220. ProxyMaster 240, on receiving the CPRI bit stream transmitted by RE 220,determines, at 305(2), that the end-to-end L1 synchronization has beenreached between REC 210 and RE 220 and updates the internal state of theCPRI port state machine as per CPRI Specification v7.0. The operationsat 305(2) may further include Proxy Master 240 starting to map the CPRIbit stream received from RE 220 into RoE frames (e.g., into the RoEpayload of the frames) and transmitting the RoE frames encapsulatedwithin Ethernet frames to Proxy Slave 230 via Ethernet network 250.

Recall, Proxy Slave 230, via operations at 301/302, has been continuingto frame the REC 210 transmitted CPRI bit stream for a CPRI link bitrate (as varied by REC 210 through the T1 time intervals) in RoE frameswith the link bit rate information included in the RoE header of theframes and transmitting the RoE frames (encapsulated within Ethernetframes) towards Proxy Master 240/RE 220. At 305(3), the operationsinclude Proxy Slave 230 receiving the RoE frames from Proxy Master 240and, on receiving the RoE frames, Proxy Slave 230 beginning to de-mapthe received RoE frames and start playing out (e.g., transmitting) theCPRI bit stream from the RoE frames towards REC 210. Proxy Slave 230also updates the internal state of the CPRI port state machine per CPRISpecification v7.0 indicating L1 sync is achieved from the RE 220 side.

When REC 210 is be able to receive and decode the Proxy Slave 230transmitted CPRI bit stream, which was originally initiated by RE 220,the L1 link auto-negotiations will be considered complete as both REC210 and RE 220 are able to communicate with each other via anestablished CPRI link. The operations may further include REC 210 and RE220 performing CPRI higher layer (e.g., L2 frame alignment/sync, vendorspecific negotiations, etc.) synchronization following completion of theL1 link negotiations culminating in the established CPRI link.

As illustrated in FIG. 3, Proxy Slave 230 and Proxy Master 240 mayfacilitate L1 link auto-negotiation between REC 210 and RE 220 tofacilitate CPRI link establishment between REC 210 and RE 220 forfronthaul network 200. Features associated with operations 300 forfacilitating the L1 link auto-negotiation operations between REC 210 andRE 220 may include, as discussed at 301, after reaching HFN sync withREC 210, Proxy Slave 230 does not transmit a CPRI bit stream back to REC210 at the link bit rate, rather Proxy Slave 230 starts packetizing theCPRI bit stream received from REC 210 in RoE frames and transmits theRoE frames towards RE 220 by way of Proxy Master 240. Such operationsare a change in the general CPRI port state machine configured for ProxySlave 230 in that Proxy Slave 230 should not transmit back towards theREC 210 at 301 as that would enable achieving HFN sync with REC 210.Rather Proxy Slave 230 waits until RoE frames are received from ProxyMaster 240 before it transmits a CPRI bit stream towards REC 210 (e.g.,305(2) and 305(3)).

Thus, Proxy Slave 230 and Proxy Master 240 play specific roles to enablethe L1 link auto-negotiation operations; thereby providing for theability for HFN sync by REC 210 to be achieved for the CPRI bit streamas is transmitted by RE 220.

By providing changes in operations of the CPRI port state machine atProxy Slave 230 rather than REC 210, features associated with L1 linkauto-negotiation as described herein may be achieved without affectingproprietary vendor developed REC and RE units.

As discussed at 302, Proxy Slave 230 also indicates the current CPRIlink bit rate in the RoE header of RoE frames transmitted toward ProxyMaster 240, which indicates the link bit rate that Proxy Master 240 isto use for the CPRI bit stream transmitted to RE 220 (at 303). Bydecoding the CPRI link bit rate information from the RoE header, ProxyMaster 240 can transmit a CPRI bit stream to RE 210 as per thedetermined link bit rate using the radio data contents of the receivedRoE frame; thereby providing for the ability for RE 220 to achieve HFNsync at the link bit rate transmitted by REC 210.

Referring to FIGS. 4A-4C, FIGS. 4A-4C are simplified diagramsillustrating example details associated with an Ethernet frame 400including a RoE frame 410 that may be used to communicate link bit rateinformation, according to an example embodiment. Reference is also madeto FIGS. 2-3 in connection with the description of FIGS. 4A-4C.

FIG. 4A includes Ethernet frame 400 within which RoE frame 410 isencapsulated, according to an example embodiment. Ethernet frame 400include various fields including, but not limited to, a DestinationAddress (DA) field 402, a Source Address (SA) field 404, an EthernetType (EtherType) field 406, and a Frame Check Sequence (FCS) field 408.Ethernet frame 400 includes RoE frame 410 encapsulated therein. RoEframe 410 includes a RoE header 412 and a RoE payload 414.

In at least one embodiment of Ethernet frame 400, DA field 402 may beset to the destination Media Access Control (MAC) address for thedestination node (e.g., Proxy Master 240 or Proxy Slave 230), dependingon whichever node to which the RoE frame is to be transmitted; the SAfield 404 may be set to the source MAC address for the source node(e.g., Proxy Master 240 or Proxy Slave 230), depending on whichever nodefrom which the RoE frame is transmitted; the EtherType field 406 may beset to type ‘0xFC3D’, indicating an RoE EtherType; and the FCS field 408may be set according to a cyclic redundancy check value, which can beset/computed based on various fields, data, etc. of the Ethernet frame400.

In at least one embodiment, RoE header 412 includes various fieldsincluding a Packet Sub Type (subType) field 420, a Flow Identifier(flowID) field 422, a Length field 424, and an Ordering Information(orderInfo) field 426.

FIG. 4B illustrates other example details associated with RoE frame 410including RoE header 412 and RoE payload 414, according to an exampleembodiment. In at least one embodiment, subType field 420 may be set toindicate a RoE structure-agnostic data sub type indicating that RoEpayload 414 includes a radio data payload packet, flowID field 422 maybe set to a value indicating a flow/connection between Proxy Slave 230and Proxy Master 240, and Length field 424 may be set to a value basedon the RoE payload 414 size. The RoE payload 414 includes packetizedradio data (e.g., CPRI bit stream) mapped therein.

According to the IEEE 1914 standards, the orderInfo field 426 is a32-bit field that can contain sequence number information or timestampinformation carried with each RoE frame 410. In general, the sequencenumber information can be used to identify the order of successivepackets. For sequence number information contained in RoE header 412,orderInfo field 426 contains a 32-bit Sequence Number (seqNum) field 426a , as illustrated in FIG. 4C. Thus, orderInfo field 426 can beconfigured as seqNum field 426 a , in at least one embodiment.

As illustrated in FIG. 4C, seqNum field 426 a (of orderInfo field 426)includes a p-counter field 430 having a number of p-bits that can beused to indicate a p-counter value, a q-counter field 431 having numberof q-bits that can be used to indicate a q-counter value, and anoptional reserved bits field 432 having 4-bits that can be used, in atleast one embodiment, to carry CPRI link bit rate information.

For structure-agnostic CPRI mapping, the RoE frame header field is theideal place to carry CPRI link bit rate information. The informationabout the link bit rate is to be carried in data plane because usage ofany out-of-band control plane channel will cause un-deterministic delaysfor this byte and frame alignment centric time sensitive linknegotiation procedure.

The contents of the p-counter field 430 and the q-counter field 431 arespecified by the IEEE 1914.3 Specification. However, the contents of theoptional reserved bits field 432 are not specified by the IEEE 1914.3Specification. Additionally, as per the IEEE 1914.3 Specification, thenumber of p-bits that can be used for the p-counter field 430 and thenumber of q-bits that can be used for the q-counter field 431, whichindicate the size of p and q-counter fields 430, 431, respectively, isflexible (e.g., the values/sizes can be varied). Any values that canclearly indicate the start of a radio frame boundary and the sequencingof the frames can be used in a RoE mapper/de-mapper implementation.

Accordingly, in at least one embodiment, the 4-bits of the optionalreserved bits field 432 of the sequNum field 426 a (of the orderInfofield 426) in the RoE header 412 can be used to carry CPRI link bit rateinformation within RoE frames transmitted from Proxy Slave 230 to ProxyMaster 240 during L1 link auto-negotiation operations.

In at least one embodiment, CPRI link bit rate information carried inthe optional reserved bits field 432 may be a value indicating a CPRIlink bit rate option. Per CPRI Specification v7.0, currently supportedCPRI link bit rate options (in Megabits per second (Mbit/s) includeeleven (11) link bit rate options, as follows:

1. CPRI link bit rate option 1: 614.4 Mbit/s, 8B/10B line coding

2. CPRI link bit rate option 2: 1228.8 Mbit/s, 8B/10B line coding

3. CPRI link bit rate option 3: 2457.6 Mbit/s, 8B/10B line coding

4. CPRI link bit rate option 4: 3072.0 Mbit/s, 8B/10B line coding

5. CPRI link bit rate option 5: 4915.2 Mbit/s, 8B/10B line coding

6. CPRI link bit rate option 6: 6144.0 Mbit/s, 8B/10B line coding

7. CPRI link bit rate option 7: 9830.4 Mbit/s, 8B/10B line coding

8. CPRI link bit rate option 7A: 8110.08 Mbit/s, 64B/66B line coding

9. CPRI link bit rate option 8: 10137.6 Mbit/s, 64B/66B line coding

10. CPRI link bit rate option 9: 12165.12 Mbit/s, 64B/66B line coding

11. CPRI link bit rate option 10: 24330.24 Mbit/s, 64B/66B line coding

In at least one embodiment, the binary value of ‘0000b’ for the 4-bi-tsof the optional reserved bits field 432 may be reserved and the valuesfrom one (1) (e.g., binary ‘0001b’) onwards may be used for mapping to aCPRI link bit rate option. Considering 11 rates currently supported byCPRI Specification v7.0, use of the 4-bits of the optional reserved bitsfield 432 may be sufficient and also allow for support of 4 additionalrates in the future. Thus, the value indicating the CPRI link bit rateoption may be included within 1 to 4-bits of the optional reserved bitsfield 432 (e.g., depending on the value to be included).

Use of the 4-bits of the of the optional reserved bits field 432 areonly to be used during link negotiation operations and are not to beused for this purpose when the CPRI link is up (e.g., established)between REC 210 and RE 220.

In at least one embodiment, each of the Proxy Slave 230 and the ProxyMaster 240 can be configured with a CPRI link bit rate options tablethat identifies each of a given value (e.g, values 1-11) that isassociated with each of a given CPRI link bit rate option for each of agiven CPRI link bit rate that may be used within fronthaul network 200.For example, during L1 link auto-negotiation operations, Proxy Slave 230can use its CPRI link bit rate options table to determine a value for agiven link bit rate in use (e.g., the rate of the CPRI bit streamtransmitted by REC 210 for which a HFN sync is achieved by Proxy slave230) in order for Proxy Slave 230 to include the value in the optionalreserved bits field of a seqNum field for an orderInfo field of an RoEheader of an RoE frame for each Ethernet frame that is transmitted toProxy Master 240. Proxy Master 240, upon receiving an Ethernet frameduring L1 link auto-negotiation operations can determine (e.g., decodeor identify) the link bit rate in use (by the REC 210) by performing alook-up on its CPRI bit rate options table using the value included inan RoE header of the RoE frame within the Ethernet frame in order totransmit (after de-mapping from the RoE payload) the CPRI bit stream toRE 220 at the identified link bit rate.

This use of 4 optional reserved bits does not violate the IEEE 1914.3standard and also leaves enough bits for use as p/q-bits, which shouldbe sufficient for the desired objective of orderInfo field 426 (e.g.,for carrying sequence number information via the p/q-bits of thep-counter field 430 and the q-counter field 431).

Thus, use of reserved bits in the seqNum field 426 a from orderInfofield 426 in the RoE header 412 provides for the ability for Proxy Slave230 to indicate the link bit rate in use to Proxy Master 240 during L1link auto-negotiation operations such as operations as discussed aboveat 301 and 302 of FIG. 3.

Referring to FIG. 5, FIG. 5 is a simplified flowchart illustratingexample operations 500 to provide link establishment between a radioequipment controller and a radio equipment in a fronthaul network,according to an example embodiment. In at least one embodiment,operations 500 can be performed via a Proxy Master, a Proxy Slave, aradio equipment controller (REC), a radio equipment (RE), and anEthernet network for a fronthaul network, such as Proxy Master 240,Proxy Slave 230, REC 210, RE 220, and Ethernet network 250 for fronthaulnetwork 200 as illustrated in FIGS. 2-3.

In at least one embodiment prior to the start of operations 500, it isassumed that: the Proxy Slave and the Proxy Master are configured orotherwise synchronized using a control protocol to have common subset oflink bit rates (e.g., they do not necessarily have to have the same setof link bit rates); the same RoE mapperType value is set to be the sameat both the Proxy Slave and the Proxy Master (i.e., both support thesame mapperType mode of either the Tunneling mode or the Line codingaware mode, as specified in the IEEE 1914 standards); packet-basedcommunication between the Proxy Slave and the Proxy Master via theEthernet network is operational; the radio equipment controller and theRadio Equipment of varied link bit rate capabilities are set up andready for Layer 1 link negotiations in the fronthaul network; and a CPRIlink bit rate options table is configured for each of the Proxy Slaveand the Proxy Master in which each table is configured to identify eachof a given value that is to be associated with each of a given CPRI linkbit rate option for each of a given CPRI link bit rate that may be usedwithin the fronthaul network.

In at least one embodiment, operations 500 may begin at 502 and mayinclude performing, for one or more link bit rates of a plurality oflink bit rates configured for the fronthaul network, CPRI Layer 1 linkauto-negotiation operations (510) to establish a CPRI link between theradio equipment controller and the radio equipment of the fronthaulnetwork.

In at least one embodiment, the CPRI Layer 1 link auto-negotiationoperations 510 may include at 512, achieving, by the Proxy Slave, ahyper frame number synchronization with the radio equipment controllerat a link bit rate for a first CPRI bit stream transmitted by the radioequipment controller to the Proxy Slave. The operations at 512 are aniterative process that continue to be performed between the Proxy Slaveand the radio equipment controller until a hyper frame numbersynchronization is achieved for a second CPRI bit stream transmittedfrom the Proxy Slave to the radio equipment controller, as discussedfurther below. The Proxy Slave does not transmit back to the radioequipment controller when the hyper frame number synchronization isachieved at 512; rather the operations can include the Proxy Slavewaiting until RoE frames are received from the Proxy Master beforetransmitting back to the radio equipment controller (e.g., transmittingthe second CPRI bit stream contained in the RoE frames received from theProxy Master, discussed below) at the link bit rate for which the hyperframe number synchronization is achieved for the first CPRI bit streamreceived from the radio equipment controller.

At 514, the operations may include, upon the proxy slave achieving thehyper frame number synchronization with the radio equipment controllerfor the first bit stream at the link bit rate, communicating the firstCPRI bit stream and the link bit rate from the Proxy Slave to the ProxyMaster. In at least one embodiment, the operations at 514 can includethe Proxy Slave mapping the first CPRI bit stream into the RoE payloadof RoE frames using structure-agnostic RoE mapping operations andincluding link bit rate information associated with the link bit ratewithin each RoE header of each RoE frame during the L1 linkauto-negotiation operations 510. In at least one embodiment, the linkbit rate information can be included as a value indicating a link bitrate option in which the value can be included within 1 to 4-bits (e.g.,depending on the value to be included) of an optional reserved bitsfield of a seqNum field for a orderInfo field of an RoE header. Theoperations at 514 can further include encapsulating each RoE framewithin an Ethernet frame and communicating each Ethernet frame to theProxy Master from the Proxy Slave via the Ethernet network.

At 516, the operations may include transmitting, by the proxy master,the first CPRI bit stream to the radio equipment at the link bit rate.The operations at 516 may be performed provided that the proxy masterhas the link bit rate configured in its link bit rate table. If the linkbit rate received is not something that it supports, it will nottransmit the CPRI bit stream towards the radio equipment. In at leastone embodiment, the operations at 516 can include the Proxy Masterreceiving each RoE frame and determining the link bit rate via the RoEheader for the RoE frame (e.g., by performing a look-up using the valueincluded in the optional reserved bits field of the seqNum field for theorderInfo field), determining that it supports the link bit rate, andde-mapping the CPRI bit stream from the RoE payload for the RoE frame(e.g., using structure-agnostic RoE de-mapping operations) in order totransmit the first CPRI bit stream to the radio equipment at the linkbit rate identified in the RoE header. At 518, the operations mayinclude, the radio equipment, upon achieving a hyper frame numbersynchronization for the received first CPRI bit stream at the link bitrate, transmitting a second CPRI bit stream to the Proxy Master.

At 520, the operations may include, upon the Proxy Master achieving ahyper frame number synchronization with the radio equipment for thesecond CPRI bit stream transmitted by the radio equipment at the linkbit rate, communicating the second CPRI bit stream from the Proxy Masterto the Proxy Slave. In at least one embodiment, the operations at 520can include the Proxy Master mapping the second CPRI bit stream receivedfrom the radio equipment into the RoE payload of RoE frames usingstructure-agnostic RoE mapping operations, encapsulating each RoE frameinto an Ethernet frame, and communicating each Ethernet frame to theProxy Slave via the Ethernet network.

At 522, the operations may include, transmitting, by the Proxy Slave,the second CPRI bit stream to the radio equipment controller. In atleast one embodiment, the operations at 522 may include the Proxy Slavede-mapping the second CPRI bit stream from the RoE payload for each RoEframe (e.g., using structure-agnostic RoE de-mapping operations)received from the Proxy Master and transmitting the second CPRI bitstream to the radio equipment controller at the link bit rate at whichthe Proxy Slave has achieved a hyper frame number synchronization forthe CPRI first bit stream transmitted from the radio equipmentcontroller to the Proxy Slave.

At 524, the operations may include determining, by the radio equipmentcontroller, whether a hyper frame number synchronization is achieved bythe radio equipment controller for the second CPRI bit stream receivedfrom the Proxy Slave at the link bit rate. In at least one embodiment,the operations at 524 can include the radio equipment controllerattempting to perform four consecutive detections of the SYNC bytewithin the received second CPRI bit stream. If the radio equipmentcontroller is unable to perform the four consecutive detections withinthe T1 transmit time interval (e.g., 0.9-1.1 seconds), it is determinedat 524 that the hyper frame number synchronization is not achieved andthe radio equipment controller begins to transmit the first CPRI bitstream at the next link bit rate from its configured capability set(e.g., the next highest rate, if available, in the round robin manner,as discussed above), and the operations continue to be performed at 512at which the Proxy Slave continues Layer 1 link negotiations with theradio equipment controller to achieve a hyper frame numbersynchronization with the radio equipment controller at the next link bitrate for the first CPRI bit stream transmitted by the radio equipmentcontroller and the operations continue therefrom as discussed above.

If, at 524, the radio equipment controller determines that the hyperframe number synchronization is achieved, the operations can continue to504, at which the Layer 1 link auto-negotiations are completed and theCPRI link is established between the radio equipment controller and theradio equipment that allows bi-directional traffic (e.g., radio data) tobe communicated between the radio equipment controller and the radioequipment when the radio equipment controller achieves a hyper framenumber synchronization for the second CPRI bit stream transmitted by theproxy slave at a particular link bit rate.

At 506, the operations may include the Proxy Slave and the Proxy Masterperforming normal operations (e.g., performing higher layer CPRI and/orvendor specific negotiation operations, transmitting/receiving CPRI bitstreams, performing mapping/de-mapping operations,transmitting/receiving Ethernet frames, monitoring for Layer 1 linkalarms, etc.) to facilitate radio data communications between the radioequipment controller and the radio equipment. In at least oneembodiment, operations at 506 include, the proxy slave not communicatingthe link bit rate to the proxy master during normal operations.

Referring to FIG. 6, FIG. 6 is a simplified flow chart illustratingexample operations to communicate link bit rate information using a RoEheader of a RoE frame, according to an example embodiment. In at leastone embodiment, operations 600 can be performed via a first proxy node(e.g., a Proxy Slave), a second proxy node (e.g., a Proxy Master), andan Ethernet network for a fronthaul network, such as Proxy Slave 230,Proxy Master 240, and Ethernet network 250 for fronthaul network 200 asillustrated in FIGS. 2-3.

For operations 600, it is assumed that link auto-negotiation operationsare being performed to establish a CPRI link between a radio equipmentcontroller and a radio equipment in the fronthaul network and that aCPRI link bit rate options table is configured for each of the firstproxy node and the proxy node in which each table is configured toidentify each of a given value that is to be associated with each of agiven CPRI link bit rate option for each of a given CPRI link bit ratethat may be used or supported within the fronthaul network.

In at least one embodiment, operations 600 may begin at 602 and mayinclude determining CPRI link bit rate information to communicate fromthe first proxy node to the second proxy node. In at least oneembodiment, the CPRI link bit rate information may be a value that isassociated with to a particular CPRI link bit rate option that isassociated with a particular CPRI link bit rate within the CPRI link bitrate options table configured for the first proxy node. For example, thefirst proxy node can determine CPRI link bit rate information tocommunicate to the second proxy node based on a CPRI link bit rate atwhich the first proxy node has achieved a hyper frame number sync for aCPRI bit stream received by the first proxy node (e.g., a CPRI bitstream transmitted from the radio equipment controller to the firstproxy node) and the first proxy node performing a look-up using the CPRIlink bit rate options table to determine a corresponding value (e.g.,option number) that is associated with the CPRI link bit rate.

The operations may include, at 604, the first proxy node providing theCPRI link bit rate information within a RoE header of a RoE frame. In atleast one embodiment, the link bit rate information may be providedwithin the optional reserved bits field of a seqNum field for anorderInfo field within the RoE frame. For example, the first proxy nodecan include the value determined from the CPRI link bit rate optionstable look-up within the optional reserved bits field of a seqNum fieldfor an orderInfo field within the RoE frame.

At 606, the operations may include the first proxy node mapping a CPRIbit stream into the RoE payload of the RoE frame. In at least oneembodiment, the first proxy node can map the CPRI bit stream into theRoE payload using structure-agnostic RoE mapping operations, asprescribed by the IEEE 1914 standards. At 608, the operations mayinclude the first proxy node encapsulating the RoE frame into anEthernet frame. At 610, the operations may include the first proxy nodetransmitting the Ethernet frame to the second proxy node.

At 612, the operations may include the second proxy node determining theCPRI link bit rate information from the RoE header. In at least oneembodiment, the operations at 612 can include the second proxy nodede-encapsulating the RoE frame from the Ethernet frame and performing alook-up on its CPRI link bit rate options table based on the valueincluded in the optional reserved bits field of the seqNum field for theorderInfo field within the RoE frame to determine the CPRI link bitrate. In at least one embodiment, the determined the CPRI link bit ratecan be used by the second proxy node to transmit the CPRI bit streamincluded in the RoE payload (once de-mapped from the RoE payload) to aradio equipment in order to facilitate other link auto-negotiationoperations, as discussed herein.

Referring to FIG. 7, FIG. 7 is a simplified block diagram illustratingexample details associated with a proxy node such as a Proxy Master 700for implementing operations described herein, according to an exampleembodiment. Proxy Master 700 may provide operations associated with aProxy Master within a fronthaul network as discussed herein such as, forexample, Proxy Master 240 of fronthaul network 200, as illustrated inFIG. 2.

The embodiment of FIG. 7 illustrates Proxy Master 700, which includesone or more processor(s) 702, one or more memory element(s) 704, a bus706, one or more network interface element(s) 708, and storage 710.Memory element(s) 704 may include instructions for proxy master logic720 and master link auto-negotiation logic 722. Memory element(s) 704may also include a CPRI link bit rate options table 724.

In at least one embodiment, processor(s) 702 is/are at least onehardware processor configured to execute various tasks, operations,and/or functions for Proxy Master 700 according to software and/orinstructions configured for Proxy Master 700. In at least oneembodiment, memory element(s) 704 is/are configured to store data,information, software and/or instructions associated with Proxy Master700 and logic configured for memory element(s) 704. In at least oneembodiment, bus 706 can be configured as an interface that enables oneor more elements of Proxy Master 700 (e.g., network interface element(s)708, processor(s) 702, memory element(s) 704 (and logic, etc. configuredtherein), etc.) to communicate in order to exchange information and/ordata, to perform operations, etc. In at least one embodiment, a fastkernel-hosted interconnect may be employed for Proxy Master 700,potentially using shared memory between processes (e.g., logic, etc.),which can enable efficient communication paths between the processes.

In various embodiments, network interface element(s) 708 enablescommunications (wired or wireless) between Proxy Master 700 and othernetwork elements or nodes, via one or more input/output (I/O) elements712 (e.g., any number/combination of CPRI ports, Ethernet ports,transceivers, etc.) at which data, information, etc. is received andtransmitted to facilitate operations discussed for various embodimentsdescribed herein. In various embodiments, network interface element(s)708 (e.g., hardware, software, firmware, logic, etc.) can be configuredto include any combination of Ethernet interface elements, CPRIinterface elements, Radio Frequency (RF) interface elements (e.g., forWiFi or any other unlicensed spectrum communications, for 3GPP or anyother licensed spectrum communications, and/or or any other similarnetwork interface elements to enable communications (e.g., CPRI bitstream/RoE frame mapping/de-mapping, Ethernet frameencapsulation/de-encapsulation, etc.) for Proxy Master 700 within afronthaul network (e.g., fronthaul network 200). Proxy Master 700 caninclude any suitable interfaces for receiving, transmitting, and/orotherwise communicating data and/or information in a networkenvironment.

In various embodiments, storage 710 can be configured to store data,information and/or instructions associated with Proxy Master 700 and/orlogic configured for memory element(s) 704. Note that in certainexamples, storage 710 can be consolidated with memory elements 704 (orvice versa), and/or the storage/memory elements can overlap/exist in anyother suitable manner.

In at least one embodiment, CPRI link bit rate options table 724 mayinclude a table in which each of a given value that is to be associatedwith each of a given CPRI link bit rate option for each of a CPRI linkbit rate that may be used or supported within a fronthaul network (e.g.,each of values 1-11 associated with each of 1-11 CPRI link bit rateoptions for each of 1-11 supported CPRI link bit rates as prescribed byCPRI Specification v7.0).

In various embodiments, proxy master logic 720 can include instructionsthat, when executed (e.g., by processor(s) 702) cause Proxy Master 700to perform operations, which can include, but not be limited to:performing control, management, etc. operations associated with ProxyMaster 700 (e.g., for CPRI bit steam/RoE frame mapping/de-mappingoperations, Ethernet frame encapsulations/de-encapsulations, monitoringoperations, and/or any other normal operations); cooperating and/orinteracting with other logic (internal and/or external to Proxy Master700) and/or network interface element(s) 708 (e.g., for CPRI bitstream/RoE frame mapping/de-mapping operations, Ethernet frameencapsulations/de-encapsulations, monitoring operations, and/or anyother normal operations); maintaining and/or interacting with storeddata, information, and/or parameters (e.g., link bit rates);combinations thereof; and/or the like to facilitate operations asdiscussed for various embodiments described herein.

In various embodiments, master link auto-negotiation logic 722 mayinclude instructions that, when executed (e.g., by processor(s) 702) mayfacilitate various link auto-negotiation operations described hereinincluding, but not limited to: operations associated with linkauto-negotiations performed by a Proxy Master described herein;determining a link bit rate based on link bit rate information includedin an RoE header; cooperating and/or interacting with other logic(internal and/or external to Proxy Master 700) and/or network interfaceelement(s) 708; maintaining and/or interacting with stored data,information, and/or parameters; combinations thereof; and/or the like tofacilitate operations as discussed for various embodiments describedherein.

In various embodiments, memory element(s) 704 may include any suitablememory element such as random access memory (RAM), dynamic RAM (DRAM),static RAM (SRAM), and/or cache memory. In general, memory element(s)704 can include any suitable volatile or non-volatile computer readablestorage media, which may be inclusive of non-transitory tangible mediaand/or non-transitory computer readable storage media that is capable ofstoring program/logic/software instructions and/or digital information.

In various embodiments, storage 710 may include any suitable storagesuch as persistent storage, which may be a magnetic disk drive, a solidstate hard drive, a semiconductor storage device, read only memory(ROM), an erasable programmable read only memory (EPROM), flash memory,or any other computer readable storage media, which may be inclusive ofnon-transitory tangible media and/or non-transitory computer readablestorage media, that is capable of storing program/logic/softwareinstructions and/or digital information. In some embodiments, the mediaused by storage 710 may also be removable. For example, a removable harddrive may be used for storage 710. Other examples include optical andmagnetic disks, thumb drives, and smart cards that are inserted into adrive for transfer onto another computer readable storage medium that isalso part of storage 710.

Referring to FIG. 8, FIG. 8 is a simplified block diagram illustratingexample details associated with a proxy node such as a Proxy Slave 800for implementing operations described herein, according to an exampleembodiment. Proxy Slave 800 may provide operations associated with aProxy Slave within a fronthaul network as discussed herein such as, forexample, Proxy Slave 230 of fronthaul network 200, as illustrated inFIG. 2.

The embodiment of FIG. 8 illustrates Proxy Slave 800, which includes oneor more processor(s) 802, one or more memory element(s) 804, a bus 806,one or more network interface element(s) 808, and storage 810. Memoryelement(s) 804 may include instructions for proxy slave logic 820 andslave link auto-negotiation logic 822.

In at least one embodiment, processor(s) 802 is/are at least onehardware processor configured to execute various tasks, operations,and/or functions for Proxy Slave 800 according to software and/orinstructions configured for Proxy Slave 800. In at least one embodiment,memory element(s) 804 is/are configured to store data, information,software and/or instructions associated with Proxy Slave 800 and logicconfigured for memory element(s) 804. In at least one embodiment, bus806 can be configured as an interface that enables one or more elementsof Proxy Slave 800 (e.g., network interface element(s) 808, processor(s)802, memory element(s) 804 (and logic etc. configured therein), etc.) tocommunicate in order to exchange information and/or data, to performoperations, etc. In at least one embodiment, a fast kernel-hostedinterconnect may be employed for Proxy Slave 800, potentially usingshared memory between processes (e.g., logic, etc.), which can enableefficient communication paths between the processes.

In various embodiments, network interface element(s) 808 enablescommunications (wired or wireless) between Proxy Slave 800 and othernetwork elements or nodes, via one or more input/output (I/O) elements812 (e.g., any number/combination of CPRI ports, Ethernet ports,transceivers, etc.) at which data, information, etc. is received andtransmitted to facilitate operations discussed for various embodimentsdescribed herein. In various embodiments, network interface element(s)808 (e.g., hardware, software, firmware, logic, etc.) can be configuredto include any combination of Ethernet interface elements, CPRIinterface elements, RF interface elements (e.g., for WiFi or any otherunlicensed spectrum communications, for 3GPP or any other licensedspectrum communications, and/or or any other similar network interfaceelements to enable communications (e.g., CPRI bit stream/RoE framemapping/de-mapping, etc.) for Proxy Slave 800 within a fronthaul network(e.g., fronthaul network 200). Proxy Slave 800 can include any suitableinterfaces for receiving, transmitting, and/or otherwise communicatingdata and/or information in a network environment.

In various embodiments, storage 810 can be configured to store data,information and/or instructions associated with Proxy Slave 800 and/orlogic configured for memory element(s) 804. Note that in certainexamples, storage 810 can be consolidated with memory elements 804 (orvice versa), and/or the storage/memory elements can overlap/exist in anyother suitable manner.

In at least one embodiment, CPRI link bit rate options table 824 mayinclude a table in which each of a given value that is to be associatedwith each of a given CPRI link bit rate option for each of a CPRI linkbit rate that may be used or supported within a fronthaul network (e.g.,each of values 1-11 associated with each of 1-11 CPRI link bit rateoptions for each of 1-11 supported CPRI link bit rates as prescribed byCPRI Specification v7.0).

In various embodiments, proxy slave logic 820 can include instructionsthat, when executed (e.g., by processor(s) 802) cause Proxy Slave 800 toperform operations, which can include, but not be limited to: performingcontrol, management, etc. operations associated with Proxy Slave 800(e.g., for CPRI bit steam/RoE frame mapping/de-mapping operations,Ethernet frame encapsulations/de-encapsulations, monitoring operations,and/or any other normal operations); cooperating and/or interacting withother logic (internal and/or external to Proxy Slave 800) and/or networkinterface element(s) 808 (e.g., for CPRI bit stream/RoE framemapping/de-mapping operations, Ethernet frameencapsulations/de-encapsulations, monitoring operations, and/or anyother normal operations); maintaining and/or interacting with storeddata, information, and/or parameters (e.g., link bit rates);combinations thereof; and/or the like to facilitate operations asdiscussed for various embodiments described herein.

In various embodiments, slave link auto-negotiation logic 822 mayinclude instructions that, when executed (e.g., by processor(s) 802) mayfacilitate various link auto-negotiation operations described hereinincluding, but not limited to: operations associated with linkauto-negotiations performed by a Proxy Slave described herein; includinglink bit rate information within RoE headers of RoE frames during linkauto-negotiation operations, not including link bit rate informationwithin RoE headers of RoE frames when link auto-negotiation operationsare complete; cooperating and/or interacting with other logic (internaland/or external to Proxy Slave 800) and/or network interface element(s)808; maintaining and/or interacting with stored data, information,and/or parameters; combinations thereof; and/or the like to facilitateoperations as discussed for various embodiments described herein.

In various embodiments, memory element(s) 804 may include any suitablememory element such as RAM, DRAM, SRAM, and/or cache memory. In general,memory element(s) 804 can include any suitable volatile or non-volatilecomputer readable storage media, which may be inclusive ofnon-transitory tangible media and/or non-transitory computer readablestorage media that is capable of storing program/logic/softwareinstructions and/or digital information.

In various embodiments, storage 810 may include any suitable storagesuch as persistent storage, which may be a magnetic disk drive, a solidstate hard drive, a semiconductor storage device, ROM, an EPROM, flashmemory, or any other computer readable storage media, which may beinclusive of non-transitory tangible media and/or non-transitorycomputer readable storage media, that is capable of storingprogram/logic/software instructions and/or digital information. In someembodiments, the media used by storage 810 may also be removable. Forexample, a removable hard drive may be used for storage 810. Otherexamples include optical and magnetic disks, thumb drives, and smartcards that are inserted into a drive for transfer onto another computerreadable storage medium that is also part of storage 810.

Referring to FIG. 9, FIG. 9 is a simplified block diagram illustratingexample details associated with a radio equipment controller 900 forimplementing operations described herein, according to an exampleembodiment. In at least one embodiment, radio equipment controller 900may provide operations associated with a radio equipment controllerwithin a fronthaul network as discussed herein such as, for example, REC210 of fronthaul network 200, as illustrated in FIG. 2.

The embodiment of FIG. 9 illustrates radio equipment controller 900,which includes one or more processor(s) 902, one or more memoryelement(s) 904, a bus 906, one or more network interface element(s) 908,and storage 910. Memory element(s) 904 may include instructions forradio equipment controller logic 920.

In at least one embodiment, processor(s) 902 is/are at least onehardware processor configured to execute various tasks, operations,and/or functions for radio equipment controller 900 according tosoftware and/or instructions configured for radio equipment controller900. In at least one embodiment, memory element(s) 904 is/are configuredto store data, information, software and/or instructions associated withradio equipment controller 900 and logic configured for memoryelement(s) 904. In at least one embodiment, bus 906 can be configured asan interface that enables one or more elements of radio equipmentcontroller 900 (e.g., network interface element(s) 908, processor(s)902, memory element(s) 904 (and logic etc. configured therein), etc.) tocommunicate in order to exchange information and/or data, to performoperations, etc. In at least one embodiment, a fast kernel-hostedinterconnect may be employed for radio equipment controller 900,potentially using shared memory between processes (e.g., logic, etc.),which can enable efficient communication paths between the processes.

In various embodiments, network interface element(s) 908 enablescommunications (wired or wireless) between radio equipment controller900 and other network elements or nodes, via one or more input/output(I/O) elements 912 (e.g., any number/combination of CPRI ports, Ethernetports, transceivers, etc.) at which data, information, etc. is receivedand transmitted to facilitate operations discussed for variousembodiments described herein. In various embodiments, network interfaceelement(s) 908 (e.g., hardware, software, firmware, logic, etc.) can beconfigured to include Ethernet interface elements, CPRI interfaceelements, RF interface elements (e.g., for WiFi or any other unlicensedspectrum communications, for 3GPP or any other licensed spectrumcommunications, and/or or any other similar network interface elementsto enable communications for radio equipment controller 900 within afronthaul network (e.g., fronthaul network 200). Radio equipmentcontroller 900 can include any suitable interfaces for receiving,transmitting, and/or otherwise communicating data and/or information ina network environment.

In various embodiments, storage 910 can be configured to store data,information and/or instructions associated with radio equipmentcontroller 900 and/or logic configured for memory element(s) 904. Notethat in certain examples, storage 910 can be consolidated with memoryelements 904 (or vice versa), and/or the storage/memory elements canoverlap/exist in any other suitable manner.

In various embodiments, radio equipment controller logic 920 can includeinstructions that, when executed (e.g., by processor(s) 902) cause radioequipment controller 900 to perform operations, which can include, butnot be limited to: performing control, management, etc. operationsassociated with radio equipment controller 900 (e.g., CPRI linknegotiation operations, radio equipment controller operations, and/orany other normal operations); cooperating and/or interacting with otherlogic (internal and/or external to radio equipment controller 900)and/or network interface element(s) 908 (e.g., for CPRI link negotiationoperations, radio equipment controller operations, and/or any othernormal operations); maintaining and/or interacting with stored data,information, and/or parameters (e.g., link bit rates); combinationsthereof; and/or the like to facilitate operations as discussed forvarious embodiments described herein.

In various embodiments, memory element(s) 904 may include any suitablememory element such as RAM, DRAM, SRAM, and/or cache memory. In general,memory element(s) 904 can include any suitable volatile or non-volatilecomputer readable storage media, which may be inclusive ofnon-transitory tangible media and/or non-transitory computer readablestorage media that is capable of storing program/logic/softwareinstructions and/or digital information.

In various embodiments, storage 910 may include any suitable storagesuch as persistent storage, which may be a magnetic disk drive, a solidstate hard drive, a semiconductor storage device, ROM, EPROM, flashmemory, or any other computer readable storage media, which may beinclusive of non-transitory tangible media and/or non-transitorycomputer readable storage media, that is capable of storingprogram/logic/software instructions and/or digital information. In someembodiments, the media used by storage 910 may also be removable. Forexample, a removable hard drive may be used for storage 910. Otherexamples include optical and magnetic disks, thumb drives, and smartcards that are inserted into a drive for transfer onto another computerreadable storage medium that is also part of storage 910.

Referring to FIG. 10, FIG. 10 is a simplified block diagram illustratingexample details associated with a radio equipment 1000 for implementingoperations described herein, according to an example embodiment. In atleast one embodiment, radio equipment 1000 may provide operationsassociated with radio equipment within a fronthaul network as discussedherein such as, for example, RE 220 of fronthaul network 200, asillustrated in FIG. 2.

The embodiment of FIG. 10 illustrates radio equipment 1000, whichincludes one or more processor(s) 1002, one or more memory element(s)1004, a bus 1006, one or more network interface element(s) 1008, storage1010, and a radio head 1030. Memory element(s) 1004 may includeinstructions for radio equipment logic 1020. In at least one embodiment,radio head 1030 can include circuitry, hardware, antennas, software,firmware, combinations thereof, and/or the like to provide one or moreradio transmitters and receivers to facilitate over-the-air radio accessconnectivity for user equipment.

In at least one embodiment, processor(s) 1002 is/are at least onehardware processor configured to execute various tasks, operations,and/or functions for radio equipment 1000 according to software and/orinstructions configured for radio equipment 1000. In at least oneembodiment, memory element(s) 1004 is/are configured to store data,information, software and/or instructions associated with radioequipment 1000 and logic configured for memory element(s) 1004. In atleast one embodiment, bus 1006 can be configured as an interface thatenables one or more elements of radio equipment 1000 (e.g., networkinterface element(s) 1008, processor(s) 1002, memory element(s) 1004(and logic, etc. configured therein), radio head 1030, etc.) tocommunicate in order to exchange information and/or data, to performoperations, etc. In at least one embodiment, a fast kernel-hostedinterconnect may be employed for radio equipment 1000, potentially usingshared memory between processes (e.g., logic, etc.), which can enableefficient communication paths between the processes.

In various embodiments, network interface element(s) 1008 enablescommunications (wired or wireless) between radio equipment 1000 andother network elements or nodes, via one or more input/output (I/O)elements 1012 (e.g., any number/combination of CPRI ports, Ethernetports, transceivers, etc.) at which data, information, etc. is receivedand transmitted to facilitate operations discussed for variousembodiments described herein. In various embodiments, network interfaceelement(s) 1008 (e.g., hardware, software, firmware, logic, etc.) can beconfigured to include Ethernet interface elements, CPRI interfaceelements, RF interface elements (e.g., for WiFi or any other unlicensedspectrum communications, for 3GPP or any other licensed spectrumcommunications, and/or or any other similar network interface elementsto enable communications for radio equipment 1000 within a fronthaulnetwork (e.g., fronthaul network 200). Radio equipment 1000 can includeany suitable interfaces for receiving, transmitting, and/or otherwisecommunicating data and/or information in a network environment.

In various embodiments, storage 1010 can be configured to store data,information and/or instructions associated with radio equipment 1000and/or logic configured for memory element(s) 1004. Note that in certainexamples, storage 1010 can be consolidated with memory elements 1004 (orvice versa), and/or the storage/memory elements can overlap/exist in anyother suitable manner.

In various embodiments, radio equipment logic 1020 can includeinstructions that, when executed (e.g., by processor(s) 1002) causeradio equipment 1000 to perform operations, which can include, but notbe limited to: performing control, management, etc. operationsassociated with radio equipment 1000 (e.g., CPRI link negotiationoperations, radio equipment operations, and/or any other normaloperations); cooperating and/or interacting with other logic (internaland/or external to radio equipment 1000) and/or network interfaceelement(s) 1008 (e.g., for CPRI link negotiation operations, radioequipment operations, and/or any other normal operations); maintainingand/or interacting with stored data, information, and/or parameters(e.g., link bit rates); combinations thereof; and/or the like tofacilitate operations as discussed for various embodiments describedherein.

In various embodiments, memory element(s) 1004 may include any suitablememory element such as RAM, DRAM, SRAM, and/or cache memory. In general,memory element(s) 1004 can include any suitable volatile or non-volatilecomputer readable storage media, which may be inclusive ofnon-transitory tangible media and/or non-transitory computer readablestorage media that is capable of storing program/logic/softwareinstructions and/or digital information.

In various embodiments, storage 1010 may include any suitable storagesuch as persistent storage, which may be a magnetic disk drive, a solidstate hard drive, a semiconductor storage device, ROM, an EPROM, flashmemory, or any other computer readable storage media, which may beinclusive of non-transitory tangible media and/or non-transitorycomputer readable storage media, that is capable of storingprogram/logic/software instructions and/or digital information. In someembodiments, the media used by storage 1010 may also be removable. Forexample, a removable hard drive may be used for storage 1010. Otherexamples include optical and magnetic disks, thumb drives, and smartcards that are inserted into a drive for transfer onto another computerreadable storage medium that is also part of storage 1010.

In summary, presented herein are techniques that provide a method toachieve link auto-negotiation and establishment between an REC and RE inan Ethernet-based fronthaul network, in at least one embodiment. Due tothe adoption of massive Multiple-Input Multiple-Output (MIMO)technologies and huge bandwidth requirements for 5G communication,current deployments for LTE, LTE-Advanced, LTE-Advanced Pro and new 5Gtechnology based deployments need to move to packetized fronthaul basednetworks. The existing deployments of these technologies where CPRItechnology is used for interconnection between REC and RE should alsowork in Ethernet-based packetized fronthaul networks, i.e., the CPRIstreams need to be packetized and sent over the packet network towardsthe other CPRI end point in packets where the CPRI stream will beextracted again and passed to the actual CPRI end point (REC/RE). Thismay allow for better adoption of 5G in the already existing networkdeployments.

While, the IEEE 1914.1 and IEEE 1914.3 Specifications are the standardsfor packet based fronthaul transport networks; these standards do notcover how end-to-end link negotiations can happen between REC and RE inthe fronthaul networks. Embodiments herein provide techniques to solvethis above gap. For example, a network operator can deploy CPRI-basedREC and/or RE units of varied capabilities in fronthaul network and thetechniques discussed for embodiments herein can be used to achieveend-to-end CPRI link synchronization, which otherwise would requirestatic manual configurations at each CPRI interface which is errorprone, inefficient at times, and not scalable.

In one form, a computer-implemented method is provided and may includeperforming, for one or more link bit rates of a plurality of link bitrates configured for a fronthaul network, Common Public Radio Interface(CPRI) Layer 1 link auto-negotiation operations to establish a CPRI linkbetween a radio equipment controller and a radio equipment of thefronthaul network, the CPRI Layer 1 link auto-negotiation operationscomprising: achieving, by a proxy slave, a hyper frame numbersynchronization with the radio equipment controller at a link bit ratefor a first CPRI bit stream transmitted by the radio equipmentcontroller; communicating the first CPRI bit stream and the link bitrate from the proxy slave to a proxy master; transmitting, by the proxymaster, the first CPRI bit stream to the radio equipment at the link bitrate and the radio equipment attempting to achieve a hyper frame numbersynchronization with the first CPRI bit stream; upon the radio equipmentachieving the hyper frame number synchronization, the radio equipmentcommunicating a second CPRI bit stream to the proxy master at the linkbit rate; upon the proxy master achieving a hyper frame numbersynchronization with the radio equipment for the second CPRI bit streamtransmitted by the radio equipment at the link bit rate, communicatingthe second CPRI bit stream from the proxy master to the proxy slave; andtransmitting, by the proxy slave, the second CPRI bit stream to theradio equipment controller, wherein the Layer 1 link auto-negotiationoperations are completed and the CPRI link is established between theradio equipment controller and the radio equipment when the radioequipment controller achieves a hyper frame number synchronization forthe second CPRI bit stream transmitted by the proxy slave at aparticular link bit rate.

The method may include, upon achieving the hyper frame numbersynchronization with the radio equipment controller, the proxy slavedoes not transmit to the radio equipment controller until the secondCPRI bit stream is received from the proxy master. In one embodiment,the first CPRI bit steam and the link bit rate are communicated from theproxy slave to the proxy master and the second CPRI bit stream iscommunicated from the proxy master to the proxy slave using an Ethernetnetwork. The method may further include, upon the Layer 1 linkauto-negotiation operations being completed, the proxy slave does notcommunicate the link bit rate to the proxy master. The CPRI Layer 1 linkauto-negotiation operations are performed within one transmit timeinterval of the radio equipment controller. The CPRI Layer 1 linkauto-negotiation operations may be repeated with the plurality of linkbit rates until the radio equipment controller achieves the hyper framenumber synchronization for the second CPRI bit stream transmitted by theproxy slave at the particular link bit rate.

In at least one embodiment, communicating the link bit rate includescommunicating a value indicating a link bit rate option associated withthe link bit rate. In at least one embodiment, the value indicating thelink bit rate option is included within a header of a Radio overEthernet (RoE) frame that is encapsulated within an Ethernet frame. Inat least one embodiment, the value indicating the link bit rate optionis included within a sequence number field of the header. In at leastone embodiment, the value indicating the link bit rate option isincluded within one to four bits of a sequence number field of theheader. In at least one embodiment, the value indicating link bit rateoption is included within a 4-bit sequence number field of the headerand a zero value of the 4-bit sequence number is not used.

In one form, another computer-implemented method is provided and mayinclude determining, by a first proxy node, Common Public RadioInterface (CPRI) link bit rate information to communicate from the firstproxy node to a second proxy node; providing the CPRI link bit rateinformation within a header of a Radio over Ethernet (RoE) frame; andcommunicating the RoE frame to the second proxy node. The RoE frame canbe encapsulated within an Ethernet frame. In at least one embodiment,the CPRI link bit rate information is a value indicating a CPRI link bitrate option associated with a CPRI link bit rate at which the firstproxy node has achieved a hyper frame number synchronization for a CPRIbit stream received by the first proxy node. In at least one embodiment,the value is provided within a reserved bits field of a sequence numberfield of the header.

The operations described herein may be identified based upon theapplication for which they are implemented in a specific embodiment.However, it should be appreciated that any particular operationnomenclature herein is used merely for convenience, and thus theembodiments should not be limited to use solely in any specificapplication identified and/or implied by such nomenclature.

Data relating to operations described herein may be stored within anyconventional or other data structures (e.g., files, arrays, lists,stacks, queues, records, etc.) and may be stored in any desired storageunit (e.g., database, data or other repositories, queue, etc.). The datatransmitted between entities may include any desired format andarrangement, and may include any quantity of any types of fields of anysize to store the data. The definition and data model for any datasetsmay indicate the overall structure in any desired fashion (e.g.,computer-related languages, graphical representation, listing, etc.).

The environment of the present embodiments may include any number ofcomputer, compute node, network element, or other processing systems(e.g., client or end-user systems, server systems, etc.) and databasesor other repositories arranged in any desired fashion, where the presentembodiments may be applied to any desired type of computing environment(e.g., cloud computing, client-server, network computing, mainframe,stand-alone systems, etc.). The computer or other processing systemsemployed by the present embodiments may be implemented by any number ofany personal or other type of computer or processing system (e.g.,desktop, laptop, personal digital assistant (PDA), mobile devices,etc.), and may include any commercially available operating system andany combination of commercially available and custom software (e.g.,machine learning software, etc.). These systems may include any types ofmonitors and input/output devices (e.g., keyboard, mouse, voicerecognition, etc.) to enter and/or view information.

Note that in certain example implementations, operations as outlinedherein may be implemented by logic encoded in one or more tangiblemedia, which may be inclusive of non-transitory tangible media and/ornon-transitory computer readable storage media (e.g., embedded logicprovided in an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA), in digital signal processing (DSP)instructions, firmware, software [potentially inclusive of object codeand source code] to be executed by a processor, or other similarmachine, etc.). In some of these instances, a memory element or storagecan store data used for operations described herein. This includesmemory elements or storage being able to store software, logic, code,and/or processor instructions that are executed to carry out operationsdescribed herein. A processor (e.g., a hardware processor) can executeany type of instructions associated with data to achieve the operationsdetailed herein. In one example, a processor may transform an element oran article (e.g., data, information) from one state or thing to anotherstate or thing. In another example, operations outlined herein may beimplemented with logic, which can include fixed logic, hardware logic,programmable logic, digital logic, etc. (e.g., software/computerinstructions executed by a processor) and the elements identified hereincould be some type of a programmable processor, programmable digitallogic (e.g., an FPGA, a DSP processor, an EPROM, a controller, anelectrically erasable PROM (EEPROM), or an ASIC that includes digitallogic, software, firmware, code, electronic instructions, or anysuitable combination thereof.

In one example implementation, a network element can encompass networkappliances, routers, servers, switches, gateways, bridges, loadbalancers, firewalls, processors, modules, or any other suitable device,component, element, or object operable to exchange information thatfacilitates or otherwise helps to facilitate various operations asdescribed for various embodiments discussed herein in a networkenvironment (e.g., for networks such as discussed herein).

The above description is intended by way of example only. Although thetechniques are illustrated and described herein as embodied in one ormore specific examples, it is nevertheless not intended to be limited tothe details shown, since various modifications and structural changesmay be made within the scope and range of equivalents of the claims.

Elements and/or systems discussed for various embodiments describedherein can couple to one another through simple interfaces and/orthrough any other suitable connection (wired or wireless), whichprovides a viable pathway for network communications. As referred toherein, a physical (wired or wireless) interconnection or interface canrefer to an interconnection of one element with one or more otherelement(s), while a logical interconnection or interface can refer tocommunications, interactions and/or operations of elements with eachother, which can be directly or indirectly interconnected, in a networkenvironment. Additionally, any one or more of the elements and/orsystems may be combined or removed from a given deployment based on aparticular configuration and/or implementation.

In various embodiments, networks can represent a series of points orelements of interconnected communication paths (wired or wireless) forreceiving and transmitting packets of information that propagate throughnetworks. In various embodiments, networks can be associated with and/orprovided by a single network operator or service provider and/ormultiple network operators or service providers. In various embodiments,networks can include and/or overlap with, in whole or in part, one ormore packet data network(s). A network may offer communicativeinterfaces between various elements of the network and may be associatedwith any local area network (LAN), wireless local area network (WLAN),metropolitan area network (MAN), wide area network (WAN), virtualprivate network (VPN), Radio Access Network (RAN), virtual local areanetwork (VLAN), enterprise network, Intranet, extranet, or any otherappropriate architecture or system that facilitates communications in anetwork environment

Networks through which communications propagate in can use any suitabletechnologies for communication including wireless (e.g., 3G/4G/5G/NGnetwork, Institute of Electrical and Electronics Engineers (IEEE)Standard 802.11™-2012, published Mar. 29, 2012 (e.g., WiFi), WiMax, IEEEStandard 802.16™-2012, published Aug. 17, 2012, Radio-frequencyIdentification (RFID), Near Field Communication (NFC), Bluetooth™, etc.)and/or wired (e.g., T1 lines, T3 lines, digital subscriber lines (DSL),Ethernet, etc.) communication. Generally, any suitable means ofcommunication may be used such as electric, sound, light, infrared,and/or radio.

Note that in this disclosure, references to various features (e.g.,elements, structures, nodes, modules, components, logic, steps,operations, functions, characteristics, etc.) included in ‘oneembodiment’, ‘example embodiment’, ‘an embodiment’, ‘anotherembodiment’, ‘certain embodiments’, ‘some embodiments’, ‘variousembodiments’, ‘other embodiments’, ‘alternative embodiment’, and thelike are intended to mean that any such features are included in one ormore embodiments of the present disclosure, but may or may notnecessarily be combined in the same embodiments. Note also that amodule, engine, client, controller, function, logic, or the like as usedherein, can be inclusive of an executable file comprising instructionsthat can be understood and processed on a computer, processor, machine,network element, compute node, combinations thereof, or the like and mayfurther include library modules loaded during execution, object files,system files, hardware logic, software logic, and/or any otherexecutable modules.

The embodiments presented may be implemented in various forms, such asan apparatus, a system, a method, and/or a computer program product atany possible technical detail level of integration. The computer programproduct may include a non-transitory computer readable storage medium(or media) having computer readable program instructions thereon forcausing a processor to carry out aspects of operations presented herein.

It is also important to note that the operations and steps describedwith reference to the preceding figures illustrate only some of thepossible scenarios that may be executed by, or within, a system ornetwork. Some of these operations may be deleted or removed whereappropriate, or these steps may be modified or changed considerablywithout departing from the scope of the discussed concepts. In addition,the timing of these operations may be altered considerably and stillachieve the results taught in this disclosure. The preceding operationalflows have been offered for purposes of example and discussion.Substantial flexibility is provided by the system in that any suitablearrangements, chronologies, configurations, and timing mechanisms may beprovided without departing from the teachings of the discussed concepts.

Note that with the examples provided above, as well as numerous otherexamples provided herein, interactions may be described in terms of one,two, three, or four elements. However, this has been done for purposesof clarity and example only. In certain cases, it may be easier todescribe one or more of the functionalities by only referencing alimited number of network elements. It should be appreciated thatnetworks discussed herein (and their teachings) are readily scalable andcan accommodate a large number of components, as well as morecomplicated/sophisticated arrangements and configurations. Accordingly,the examples provided should not limit the scope or inhibit the broadteachings of networks discussed herein as potentially applied to amyriad of other architectures.

As used herein, unless expressly stated to the contrary, use of thephrase ‘at least one of’, ‘one or more of’, ‘and/or’, variationsthereof, or the like are open ended expressions that are bothconjunctive and disjunctive in operation for any combination of namedelements, conditions, or activities. For example, each of theexpressions ‘at least one of X, Y and Z’, ‘at least one of X, Y or Z’,‘one or more of X, Y and Z’, ‘one or more of X, Y or Z’ and ‘A, B and/orC’ can mean any of the following: 1) X, but not Y and not Z; 2) Y, butnot X and not Z; 3) Z, but not X and not Y; 4) X and Y, but not Z; 5) Xand Z, but not Y; 6) Y and Z, but not X; or 7) X, Y, and Z.Additionally, unless expressly stated to the contrary, the terms‘first’, ‘second’, ‘third’, etc., are intended to distinguish theparticular nouns (e.g., element, condition, node, module, activity,operation, etc.) they modify. Unless expressly stated to the contrary,the use of these terms is not intended to indicate any type of order,rank, importance, temporal sequence, or hierarchy of the modified noun.For example, ‘first X’ and ‘second X’ are intended to designate two Xelements that are not necessarily limited by any order, rank,importance, temporal sequence, or hierarchy of the two elements. Furtheras referred to herein, ‘at least one of’ and ‘one or more of’ can berepresented using the ‘(s)’ nomenclature (e.g., one or more element(s)).

Although the present disclosure has been described in detail withreference to particular arrangements and configurations, these exampleconfigurations and arrangements may be changed significantly withoutdeparting from the scope of the present disclosure. For example,although the present disclosure has been described with reference toparticular communication exchanges involving certain protocols, networksdiscussed herein may be applicable to other exchanges or protocols,interfaces, and/or communications standards, proprietary and/ornon-proprietary. Moreover, although networks described herein have beenillustrated with reference to particular elements and operations thatfacilitate processes, these elements, and operations may be replaced byany suitable architecture or process that achieves the intendedfunctionality of networks described herein.

What is claimed is:
 1. A method comprising: performing, for one or morelink bit rates of a plurality of link bit rates configured for afronthaul network, Common Public Radio Interface (CPRI) Layer 1 linkauto-negotiation operations to establish a CPRI link between a radioequipment controller and a radio equipment of the fronthaul network, theCPRI Layer 1 link auto-negotiation operations comprising: achieving, bya proxy slave, a hyper frame number synchronization with the radioequipment controller at a link bit rate for a first CPRI bit streamtransmitted by the radio equipment controller; communicating the firstCPRI bit stream and the link bit rate from the proxy slave to a proxymaster; transmitting, by the proxy master, the first CPRI bit stream tothe radio equipment at the link bit rate and the radio equipmentattempting to achieve a hyper frame number synchronization with thefirst CPRI bit stream; upon the radio equipment achieving the hyperframe number synchronization, the radio equipment communicating a secondCPRI bit stream to the proxy master at the link bit rate; upon the proxymaster achieving a hyper frame number synchronization with the radioequipment for the second CPRI bit stream transmitted by the radioequipment at the link bit rate, communicating the second CPRI bit streamfrom the proxy master to the proxy slave; and transmitting, by the proxyslave, the second CPRI bit stream to the radio equipment controller,wherein the Layer 1 link auto-negotiation operations are completed andthe CPRI link is established between the radio equipment controller andthe radio equipment when the radio equipment controller achieves a hyperframe number synchronization for the second CPRI bit stream transmittedby the proxy slave at a particular link bit rate.
 2. The method of claim1, wherein upon achieving the hyper frame number synchronization withthe radio equipment controller, the proxy slave does not transmit to theradio equipment controller until the second CPRI bit stream is receivedfrom the proxy master.
 3. The method of claim 1, wherein the first CPRIbit steam and the link bit rate are communicated from the proxy slave tothe proxy master and the second CPRI bit stream is communicated from theproxy master to the proxy slave using an Ethernet network.
 4. The methodof claim 1, wherein upon the Layer 1 link auto-negotiation operationsbeing completed, the proxy slave does not communicate the link bit rateto the proxy master.
 5. The method of claim 1, wherein the CPRI Layer 1link auto-negotiation operations are performed within one transmit timeinterval of the radio equipment controller.
 6. The method of claim 1,wherein the CPRI Layer 1 link auto-negotiation operations are repeatedwith the plurality of link bit rates until the radio equipmentcontroller achieves the hyper frame number synchronization for thesecond CPRI bit stream transmitted by the proxy slave at the particularlink bit rate.
 7. The method of claim 1, wherein communicating the linkbit rate includes communicating a value indicating a link bit rateoption associated with the link bit rate.
 8. The method of claim 7,wherein the value indicating the link bit rate option is included withina header of a Radio over Ethernet (RoE) frame that is encapsulatedwithin an Ethernet frame.
 9. The method of claim 8, wherein the valueindicating the link bit rate option is included within one to four bitsof a sequence number field of the header.
 10. One or more non-transitorycomputer readable storage media encoded with instructions that, whenexecuted by a processor, cause the processor to perform operations,comprising: performing, for one or more link bit rates of a plurality oflink bit rates configured for a fronthaul network, Common Public RadioInterface (CPRI) Layer 1 link auto-negotiation operations to establish aCPRI link between a radio equipment controller and a radio equipment ofthe fronthaul network, the CPRI Layer 1 link auto-negotiation operationscomprising: achieving, by a proxy slave, a hyper frame numbersynchronization with the radio equipment controller at a link bit ratefor a first CPRI bit stream transmitted by the radio equipmentcontroller; communicating the first CPRI bit stream and the link bitrate from the proxy slave to a proxy master; transmitting, by the proxymaster, the first CPRI bit stream to the radio equipment at the link bitrate and the radio equipment attempting to achieve a hyper frame numbersynchronization with the first CPRI bit stream; upon the radio equipmentachieving the hyper frame number synchronization, the radio equipmentcommunicating a second CPRI bit stream to the proxy master at the linkbit rate; upon the proxy master achieving a hyper frame numbersynchronization with the radio equipment for the second CPRI bit streamtransmitted by the radio equipment at the link bit rate, communicatingthe second CPRI bit stream from the proxy master to the proxy slave; andtransmitting, by the proxy slave, the second CPRI bit stream to theradio equipment controller, wherein the Layer 1 link auto-negotiationoperations are completed and the CPRI link is established between theradio equipment controller and the radio equipment when the radioequipment controller achieves a hyper frame number synchronization forthe second CPRI bit stream transmitted by the proxy slave at aparticular link bit rate.
 11. The media of claim 10, wherein uponachieving the hyper frame number synchronization with the radioequipment controller, the proxy slave does not transmit to the radioequipment controller until the second CPRI bit stream is received fromthe proxy master.
 12. The media of claim 10, wherein the first CPRI bitsteam and the link bit rate are communicated from the proxy slave to theproxy master and the second CPRI bit stream is communicated from theproxy master to the proxy slave using an Ethernet network.
 13. The mediaof claim 10, wherein upon the Layer 1 link auto-negotiation operationsbeing completed, the proxy slave does not communicate the link bit rateto the proxy master.
 14. The media of claim 10, wherein communicatingthe link bit rate includes communicating a value indicating a link bitrate option associated with the link bit rate.
 15. The media of claim14, wherein the value indicating the link bit rate option is includedwithin a header of a Radio over Ethernet (RoE) frame that isencapsulated within an Ethernet frame.
 16. The media of claim 15,wherein the value indicating the link bit rate option is included withinone to four bits of a sequence number field of the header.
 17. A methodcomprising: determining, by a first proxy node, Common Public RadioInterface (CPRI) link bit rate information to communicate from the firstproxy node to a second proxy node; providing the CPRI link bit rateinformation within a header of a Radio over Ethernet (RoE) frame; andcommunicating the RoE frame to the second proxy node.
 18. The method ofclaim 17, wherein the RoE frame is encapsulated within an Ethernetframe.
 19. The method of claim 17, wherein the CPRI link bit rateinformation is a value indicating a CPRI link bit rate option associatedwith a CPRI link bit rate at which the first proxy node has achieved ahyper frame number synchronization for a CPRI bit stream received by thefirst proxy node.
 20. The method of claim 19, wherein the value isprovided within a reserved bits field of a sequence number field of theheader.